Hi there! I was wondering how to open the Black Chest in Ashbury castlegrounds in the north. I picklocked it, but it jammed.
If you wait a day after jamming something it will reset to "locked", allowing you to try again. Alternately you can break chests (or any other item with health) by selecting the attack button then holding down alt when you click on it, which will allow you to get at what's inside.